3.有性繁殖的进化雌雄有别 http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction 有性繁殖起源于120亿年前的单细胞真核生物 衣藻与蕨类的性生活 Mitosis Chlamydomonas Fern Life Cycle Sporophyte induslum Sorus with many life cycle Fronds covering a sporangia soIUs Spores Mitosis F月ddlehead Rhizome Young Dipiold (2N) Haploid (N)】 Annulus Fertilization Prothailus Sperm Germinating spore Meiosis hollow cell wall ertiltzatioe 10 Anthoridium Gametophyte2022-3-11 1 10 3. 有性繁殖的进化-雌雄有别 http://en.wikipedia.org/wiki/Evolution_of_sexual_reproduction 有性繁殖起源于 120亿年前 的单细胞真核生物 衣藻与蕨类的性生活